The invention presented here is aimed at the field of industrial automation or in any case at all fields related to the introduction of a robotized automatic system, where the demand for flexible robotized systems capable of fulfilling the most disparate requirements is growing continuously.
In particular, the industrial fields of use envisaged for the feeder according to the invention are rubber, plastics and other synthetic materials, glass, the food, cosmetic, pharmaceutical, medical industry, car components, electrical household appliances, computers, consumer electronics, metal findings, the wood industry and the furniture accessory industry, etcetera.
The need is in fact increasingly felt to feed different industrial automation systems according to different production requirements. Currently, industrial products are in fact characterized by an ever shorter lifespan, by decreasing production volumes and by the consequent need to be able to rapidly adapt the plants to the changing production requirements, while trying to minimize the costs of this adaptation.
This ease of adaptation of the plants to different production volumes and the adaptation of production to different end products are often the only economic justification that keeps an automatic production system alive, avoiding the resort to manual systems, which are generally more expensive and slower but far more versatile and force businesses to move production plants to countries where labor is cheaper.
Feeders are known which are controlled by robots of the Cartesian, anthropomorphic, cylindrical type, etcetera.
These feeders are provided with artificial vision systems, such as for example linear, matrix, 3-D and similar television cameras, which require such lighting conditions as to be able to recognize the parts by means of a television camera. The lighting conditions can be created by external lighting from above or by means of a backlighting device arranged normally below the bed that supports the parts.
The feeder is filled from the outside periodically and manually by means of a hopper, with a belt-type elevator or in other ways.
The artificial vision system recognizes the part loaded onto the feeder that is needed for production and the robot picks it up.
These known devices produce the advancement of the parts that constitute the feed for the robots by means of mechanical shaking and/or linear movement obtained by means of motorized belts.
One problem of these feeders is due to the fact that when the parts to be fed comprise at least one cylindrical portion, they tend to roll, offering statistically most frequently to the robot parts that cannot be gripped easily, failing to feed it.
With this type of feeder, be it with linear and/or vibration advancement, it is not possible to vary in all cases the position and arrangement of the parts on the surface, thus slowing the production chain, with severe costs on final production.
Moreover, due to difficult accessibility to the internal parts of known feeders, cleaning the backlighting system is more complicated, penalizing the quality of the vision system and therefore the efficiency of the production.
Another disadvantage of a device of this type is that once pickup has been performed, it is not always possible to vary easily or rapidly the position and arrangement of the parts to be gripped on the bed and therefore such parts must be returned to the production cycle together with the new load of parts to be gripped.
At the end of the pickup, therefore, the parts that have remained on the bed are unloaded from the feeder and reintroduced into the process just described so that a continuous cycle (loop) occurs.
The parts are reintroduced during the step for loading by means of chutes, ramps and other conveyor belts.
It can be deduced easily that such a method is too slow and laborious, since the pickup operation ends with the depletion of all the parts, sometimes taking an indefinite number of cycles that is difficult to predict.
In addition to this, since the robot must unload the feeder at the end of the pickup and then load it again, excessively long nonproductive times or downtimes occur.
Last but not least, due to the above, in order to return the rejected parts to the cycle it is necessary to provide a large space that is sufficient to allow the rejected parts to be transferred from the outlet to the inlet of the feeder by movement means, such as conveyor belts, ramps and chutes. These means, which often cause jammings especially during vibration, require the constant intervention of an assigned operator and therefore affect importantly the economy of the device.